From: Denys Fedoryshchenko Date: Fri, 10 Feb 2023 23:46:37 +0000 (+0200) Subject: libnetlink.c: Fix memory leak in batch mode X-Git-Tag: v6.2.0~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6d25be27cc2976ff1180a7ad27df57827ec162fa;p=thirdparty%2Fiproute2.git libnetlink.c: Fix memory leak in batch mode During testing we noticed significant memory leak that is easily reproducible and detectable with valgrind: ==2006284== 393,216 bytes in 12 blocks are definitely lost in loss record 5 of 5 ==2006284== at 0x4848899: malloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==2006284== by 0x18C73E: rtnl_recvmsg (libnetlink.c:830) ==2006284== by 0x18CF9E: __rtnl_talk_iov (libnetlink.c:1032) ==2006284== by 0x18D3CE: __rtnl_talk (libnetlink.c:1140) ==2006284== by 0x18D4DE: rtnl_talk (libnetlink.c:1168) ==2006284== by 0x11BF04: tc_filter_modify (tc_filter.c:224) ==2006284== by 0x11DD70: do_filter (tc_filter.c:748) ==2006284== by 0x116B06: do_cmd (tc.c:210) ==2006284== by 0x116C7C: tc_batch_cmd (tc.c:231) ==2006284== by 0x1796F2: do_batch (utils.c:1701) ==2006284== by 0x116D05: batch (tc.c:246) ==2006284== by 0x117327: main (tc.c:331) ==2006284== ==2006284== LEAK SUMMARY: ==2006284== definitely lost: 884,736 bytes in 27 blocks In case nlmsg_type == NLMSG_ERROR and if answer set to NULL, we should free(buf) too. Signed-off-by: Denys Fedoryshchenko Signed-off-by: Stephen Hemminger --- diff --git a/lib/libnetlink.c b/lib/libnetlink.c index c89760436..68360b0f4 100644 --- a/lib/libnetlink.c +++ b/lib/libnetlink.c @@ -1099,6 +1099,8 @@ next: if (answer) *answer = (struct nlmsghdr *)buf; + else + free(buf); return 0; }